1. Field of the Invention
The invention particularly relates to a surgical clamp of the type used in osteosynthesis and for the fixation of natural or artificial ligaments. The invention likewise relates to a device designed to drive and extract this clamp.
2. Prior Art
As is common knowledge among persons skilled in the art, surgical clamps comprise two parallel anchoring legs linked by a rectilinear part or yoke such that the clamp has the shape of an inverted-U. Leg tips are tapered into points to facilitate penetration.
Devices designed to position, drive and extract clamps for purposes of bone surgery are also know. The state of the art is illustrated by the specifications of U.S. Pat. No. 4,263,903, for instance. Basically, the clamp disclosed therein features a wedge-shaped yoke linking the legs and is designed to be inserted into the mating part of the driving device. The device features a moving part consisting of two jaws acting as pincers, said pincers being controlled by an actuator located at the end of a handle. The yoke of the surgical clamp dovetails into the jaws when the latter are closed.
Event though this solution is a satisfactory one as regards driving and extracting clamps, it appears that the wedge-shaped section of the latter comprises projecting parts that may cause tissue lesions. The drawback is the more significant when the clamp is flush with the skin. Lesions are quite frequent.
In an attempt to overcome such drawbacks, a clamp has been proposed the yoke of which, designed to be loaded into a clamp driving device, is free from asperities. The design is described in the specifications of patent FR 862764. The clamp concerned features a yoke with rounded edges on its upper half and a lower half tapering down to where the clamp legs start. The bottom of the yoke, therefore, is linked to the top by a large radius of curvature substantially representing a quadrant.
The driving device of the type described in U.S. Pat. No. 4,263,903, referred to above, features a moving part consisting of jaws acting as pincers, with the jaw insides mating the cross-section of the clamp yoke, the jaws notably featuring a large radius of curvature at their lips. The inherent risk of the design is a skewing motion of the clamp at the moment of impact, i.e., when the clamp is driven in. Indeed, the rounded edges of the yoke bottom combined with the rounded profile of the jaws gripping the yoke are unlikely to ensure a satisfactory angular hold.